Transmission for earth-boring machines



21, 1931. w JASPERT 1,801,865

TRANSMISSION FOR EARTN BORING IAOHINES Filed Oct. 21, 1924 WITNESSES:

Patented Apr. 21, 1931 a UNITED STATES PATENT OFFICE WILLIAM B.JASPER/1, O1 SWISSVALE, PENNSYLVANIA, A BSIGNOB TO WESTINGEOUSI ELEGIBIG& IANUTACTURING COMPANY, A CORPORATION 01' PENNSYLVANIA TRANSMISSION FOREARTH-BORING Cm Application fled October 21, 1924;. Serial No. 745,089.

My invention relates to transmission systems and more particularly totransmission mechanism utilized in the operation of earth boringmachines.

It is among the objects of my invention to rovide a transmission systemfor earth borlng machines which shall be of simple compact and durablemechanical construction.

Another object of my invention is to provide a transmission systemembodying a differential gear which shall have simple and improvedregulating means for differentiating the speeds and directions ofrotation of its rotating elements.

Another object of my invention is to provide a drive mechanism of theabove-designated character which shall be especially applicable to thedrive mechanism of earth oring machines in that it provides simpleconnecting means between the rotary drill table and the draw works andwhich shall have regulating means associated therewith for co-ordinatingthe function of the driven elements.

Various types of earth boring devices have been heretofore proposedutilizing a differential gear intermediate the prime mover'and thedriven elements most of which utilize a plurality of motors, one ofwhich has a primary function of rotating the drill and an auxiliaryfunction of regulating'the direction of rotation and the rate of feedingthe drill by means of the draw works through the LS differential system.

My present invention is directed to 11v transmission system which isadapted to be utilized in connection with the drive mechanism of earthboring machines that embodies a single motive device or motor andmechanical means for regulating the function of the draw works throughthe differential system.

My device is designed to provide a positive drive to the rotary tablewhich is highly desirable in controlling the torque and speed of thedrill member. The draw works such as the hoist drum which cooperateswith the drill member to feed the same by lowering it in the directionof the work is connected 50 through a differential gear mechanism to themotor. I further provide an automatic control means for the differentialto provide suitable regulation for the draw Works in accordance with theload variations of the driving motor.

In the accompanying drawings constituting a part hereof and in whichlike reference characters designate like parts, the single figure is adiagrammatic view of a transmission system embodying the principles ofmy invention.

The system therein illustrated comprises a rotary drill table 1 having arectangular opening 2 located centrally therein which is adapted toreceive a similarly shaped portion of a drill stem. The table isoperatively connected by a bevel gear 3 to a drive shaft 4 having asprocket wheel 5 mounted thereon. A drum member 6 constituting a part ofthe standard draw works, utilized in rotary drilling, is journaled forrotation by the drum shaft 7, by the journal brackets 8 secured in theusual manner to the derrick.

The end of the drum shaft is provided with a sprocket wheel 9. The drummember 6 is provided with a cable 10 which extends to the center of therotary table 1 for the purpose of lowering or raising the drill stem orcasings.

A differential gear mechanism 11 com rising a planetary system 12, and apair 0 sun gears 13 and 14 is disposed in suitable working alinementwith the drill table and drum and is operatively engaged by a pinionmember 15 to an electrical motor 16 which constitutes a motive device.The sun gears 13 and 14 are provided with extension sleeves on which asprocket wheel 17 and a magnetic brake mechanism 18 are respectivelymounted. The planetary system 12 is keyed to a drive shaft 19 which isprovided with a sprocket wheel 20. The sprockets 9 and 17 of the drumand differential and the sprockets 5 and 20 of the rotary table andshaft 19 are respectively connected by sprocket chains 21. The magneticbrake 18 is connected to the windings of the motor 16 by suitable leads22 and is of the type illustrated in detail and described in my co ndingapplication Serial Number 745,038 fi ed Oct. 21, 1924.

. follows: Assuming the drill stem to be operatively mounted in therotary table 1 and connected to the cable 10 of the drum 6 with therotary and drum shafts 4 and 7 respectively connected to the driveshafts 19 and 13 ofthe differential, then by actuating the drive motor16 the shaft 19 will rotate and the rotary table 1 will revolve, thusturning the drill member. When the magnetic brake mechanism 18 is in itsde-encrgized position, the sun gear 14 is free to rotate on the shaft 19and the sun gear 13 by virtue of its sprocket gear connection to thedrum member will rotate in the direction in which the drum is rotatin tofeed the cable in the direction of the wor The normal direction ofrotation will therefore be counter-clock wise when looking in thedirection of the planetary system from the sprocket wheel 17; and thesun gear 14 will revolve in the opposite direction while the planetarysystem 12 will rotate in a clockwise direction and in the same directionas the sun gear 14. As long as the sun gear 14 is free to rotate therewill be no transmission of power to the sun gear 13. However, when thefreedom of motion of the sun gear14 is restrained, torque willbetransmitted to the teeth of the sun gear 13 against the normal directionof operation to reverse the gear 13, thereby rotating the drum 6 in theopposite direction to hoist the cable 10, thus raising the drill awayfrom the work.

This function is effected through the magnetic brake 18, which iselectrically connected to the windings of motor 16, so that when thetorque of the motor varies with the load on the drill stem, the brakewill become energized in varying degrees or de-energized to engage orrelease the sun gear 14. For instance, if the drill member is workingthrough a relatively soft formation of shale or sand and suddenlyencounters a conglomerate of boulders or hard rock, the increased loadon the drill will react on the motor 16 and the magnetic brake 18 willoperate, responsively to the load variation of the motor,

resulting in a. gripping of the sun gear 14' to retard its motion orentirely interrupt it. The continued rotation of the motor 16,thoughperhaps slower than its normal rotation, will in an extreme case,cause a reversal of the sun gear 13, thereby reversing the direction ofthe drum 6, which will lift the weight of the drill member or entirelyremove it from the work, with the result that the load is released andthe drill immediately comes up to its normal cutting speed. The magneticbrake 18 automatically becomes relatively de-energized and releases thesun gear 14, which permits the drum to again feed the drill in theadvance direction; and normal operatin conditions are thereby againestablishe The brake mechanism drum member 6 for hoisting or auxiliaryoperations when the drill table 1 is idle.

It is evident from the foregoing description of my invention that atransmission system embodying the above principles will provide simpleand efiicient means for conducting the various operations essential toearth boring and that by the association of the magnetic control orregulating means a positive and sensitive regulating of the feedermechanism is obtained;

Although I have described a specific embodiment of my invention it willbe obvious to those skilled in the art that various modifications may bemade in the details of construction, the size and proportion of theseveral cooperating parts and the application of my device withoutdeparting from the principles herein set forth.

I claim as my invention:

In an earth-boring system, in combination, a rotary drill-table, a motorfor operating the drill-table, power-transmission means interposedbetween the motor and the drill-table, a hoisting mechanism associatedwith the drill-table to control the boring operations, means connectingthe hoisting mechanism with the power-transmission means, and brakingmeans cooperative with the power-transmission means for controlling theoperation of the hoisting mechanism, said braking means being energizedby the motor current.

2. In an earth-boring system, in combination, a rotary drill-table, amotor for operating the drill-table, a difierential transmissioninterposed between the motor and the drill-table, a hoisting mechanismdisposed to be driven by the motor through the differentialtransmission, and an electrically controlled brake cooperating with thedifferential transmission to vary the amount of power transmitted to thehoisting mechanism during the drilling operations, said brake beingresponsive, in operation, to the load current of the motor.

In testimony whereof, I have hereunto subscribed my name this 16th dayof October,

WILLIAM B. J ASPERT.

